Rebels in besieged Eastern Ghouta began surrendering yesterday in the face of a ferocious ground offensive by Bashar al-Assad's troops, as others in nearby areas negotiated their fate.

Opposition fighters in the Hammouriyeh neighbourhood became the first to agree a deal with the Syrian president's government to leave the enclave in the biggest defeat to the revolution since eastern Aleppo fell in 2016.

State TV showed the government flag flying in Hammouriyeh, where the former rebel stronghold was set to be sliced in two, cutting off thousands on the western side.

The government claimed between 30pc and 40pc had been retaken since it stepped up its operation a month ago.

Rami Abdel Rahman, head of the UK-based Syrian Observatory for Human Rights, said: "At least 700 Afghan, Palestinian, and Syrian loyalist militiamen came from Aleppo and were sent to Ghouta."

The offensive followed similar tactics used by the regime and its allies elsewhere: laying siege to rebel-held areas, subjecting them to bombardment, launching a ground assault and offering safe passage to fleeing civilians and retreating fighters.

Eastern Ghouta is close to Assad's seat of power in Damascus. More than 800 civilians have died there since the offensive began. Air strikes and mortars continued pounding heavily populated areas of the suburb yesterday, leaving a further 45 dead and dozens injured. "The situation is catastrophic," said a doctor speaking from the rebel pocket.

Panos Moumtzis, UN humanitarian co-ordinator in Syria, appealed for a ceasefire to allow in aid and medical supplies. Aid workers there said they saw desperate and hungry families hiding in their basements.

Zeid al-Hussein, a UN human rights chief, said the conflict had entered a "new phase of horror".